Need for routine pulse oximetry and oxygen delivery systems in low-income and middle-income countries
Authors: Tisungane Mvalo
Journal: The Lancet Global Health (2022)

The systematic review and meta-analysis of the prevalence of hypoxaemia among children with pneumonia in low-income and middle-income (LMIC) countries by Ahmed Ehsanur Rahman and colleagues is timely and emphasises some important current trends related to pulse oximetry and the identification of hypoxaemia in children with pneumonia.1Rahman AE Hossain AT Nair H et al.Prevalence of hypoxaemia in children with pneumonia in low-income and middle-income countries: a systematic review and meta-analysis.Lancet Glob Health. 2022; 10: e348-e359Summary Full Text Full Text PDF PubMed Scopus (2) Google Scholar Firstly, Rahman and colleagues report a high prevalence of hypoxaemia at 31% (95% CI 26–36; 101 775 children) among all children under 5 years with WHO-classified pneumonia. The prevalence was higher among patients with severe disease (41%, 95% CI 33–49; 30 483) and in emergency departments (47%, 30–64). Notably, hypoxaemia was identified in 8% (95% CI 3–16; 2395 children) of children with non-severe pneumonia. These findings are important because they provide updates to the scientific literature on hypoxaemia in childhood pneumonia in LMIC settings after the introduction of the pneumococcal conjugate vaccine and the Haemophilus influenzae type b conjugate vaccine, incorporate data after the update to the WHO childhood pneumonia diagnostic guidelines in 2014, and emphasise that a considerable proportion of patients who are classified with non-severe pneumonia merely by clinical signs (ie, in the absence pulse oximetry) would be missed for referral for inpatient care. Rahman and colleagues report a higher prevalence of hypoxaemia than that of a meta-analysis performed in 2009,2Subhi R Adamson M Campbell H Weber M Smith K Duke T The prevalence of hypoxaemia among ill children in developing countries: a systematic review.Lancet Infect Dis. 2009; 9: 219-227Summary Full Text Full Text PDF PubMed Scopus (133) Google Scholar possibly due to improved identification as a result of pulse oximetry measurement for the identification of hypoxaemia being explicitly listed in the updated WHO pneumonia diagnostic guidelines. Hypoxaemia is a well known risk factor for poor outcomes in patients with pneumonia, increasing the risk of death by approximately five times.3Lazzerini M Sonego M Pellegrin MC Hypoxaemia as a mortality risk factor in acute lower respiratory infections in children in low and middle-income countries: systematic review and meta-analysis.PLoS One. 2015; 10e0136166Crossref Scopus (66) Google Scholar Pulse oximetry implementation in LMICs is a challenge due to factors related to cost, appropriateness of child-friendly probes, and training.4King C Boyd N Walker I et al.Opportunities and barriers in paediatric pulse oximetry for pneumonia in low-resource clinical settings: a qualitative evaluation from Malawi and Bangladesh.BMJ Open. 2018; 8e019177Crossref Scopus (14) Google Scholar, 5Boyd N King C Walker IA et al.Usability testing of a reusable pulse oximeter probe developed for health-care workers caring for children <5 years old in low-resource settings.Am J Trop Med Hyg. 2018; 99: 1096-1104Crossref PubMed Scopus (4) Google Scholar Many LMIC settings still do not have adequate systems for pulse oximetry identification on presentation to health facilities. Most global childhood deaths from pneumonia occur in LMICs,6Nair H Simões EAF Rudan I et al.Global and regional burden of hospital admissions for severe acute lower respiratory infections in young children in 2010: a systematic analysis.Lancet. 2013; 381: 1380-1390Summary Full Text Full Text PDF PubMed Scopus (467) Google Scholar the same setting that is burdened with barriers to management of patients with pneumonia, of which one limitation is insufficient availability of pulse oximetry. Notably, Rahman and colleagues were not able to incorporate the investigation of types of equipment, barriers to, or limitations of pulse oximetry in their analysis. Patients with hypoxaemia require oxygen support to prevent respiratory and subsequently multiorgan failure. LMIC settings have insufficient oxygen support systems and these require strengthening in the health delivery system.7Graham HR Bagayana SM Bakare AA et al.Improving hospital oxygen systems for COVID-19 in low-resource settings: lessons from the field.Glob Health Sci Pract. 2020; 8: 858-862Crossref PubMed Scopus (16) Google Scholar This is required in the health delivery system. Hopefully, the COVID-19 pandemic has emphasised the requirement for oxygen support systems, but investigation and support are needed in this area. Oxygen is listed as an essential medication by WHO.8WHOUNICEFWHO-UNICEF technical specifications and guidance for oxygen therapy devices.https://apps.who.int/iris/bitstream/handle/10665/329874/9789241516914-eng.pdf?sequence=1&isAllowed=yDate: June 11, 2019Date accessed: January 10, 2022Google Scholar It is crucial that the intervention of oxygen support is accepted by parents and caregivers of children, because community-based misconception of oxygen support can lead to poor adherence to treatment.9Sessions KL Ruegsegger L Mvalo T et al.Focus group discussions on low-flow oxygen and bubble CPAP treatments among mothers of young children in Malawi: a CPAP IMPACT substudy.BMJ Open. 2020; 10e034545Crossref PubMed Scopus (2) Google Scholar Further investigation of factors that might be barriers to or facilitators of the implementation of oxygen support is required, because this support is key to improving pneumonia outcomes. Scientific literature on hypoxaemia has indicated the possible need to consider different cutoff points in the definition of hypoxaemia, including considering the altitude. Studies in Africa have reported that patients with pneumonia who have SpO2 levels of 90–92% have similar risks of poor outcome to patients with SpO2 levels of less than 90%.10Hooli S King C Zadutsa B et al.The epidemiology of hypoxemic pneumonia among young infants in Malawi.Am J Trop Med Hyg. 2020; 102: 676-683Crossref PubMed Scopus (8) Google Scholar Hence, further research is needed on cutoff points for hypoxaemia definitions and how different cutoff points can relate to poor outcomes of childhood pneumonia. A study in Bangladesh reported that younger children might require a different threshold of SpO2 than will older children in defining hypoxaemia, emphasising another area that might require research.11McCollum ED King C Ahmed S et al.Defining hypoxaemia from pulse oximeter measurements of oxygen saturation in well children at low altitude in Bangladesh: an observational study.BMJ Open Respir Res. 2021; 8e001023PubMed Google Scholar With the reported prevalence of hypoxaemia in children with pneumonia by Rahman and colleagues,1Rahman AE Hossain AT Nair H et al.Prevalence of hypoxaemia in children with pneumonia in low-income and middle-income countries: a systematic review and meta-analysis.Lancet Glob Health. 2022; 10: e348-e359Summary Full Text Full Text PDF PubMed Scopus (2) Google Scholar it is key for health-care providers, research experts, and policy makers to improve availability of pulse oximetry and oxygen support systems, training of clinical teams in the identification of hypoxaemia and use of oxygen support, and reliable identification of whether or which children with mild hypoxaemia (ie, SpO2 90–92%) require oxygen supplementation. This online publication has been corrected. The corrected version first appeared at thelancet.com/lancetgh on February 24, 2022 This online publication has been corrected. The corrected version first appeared at thelancet.com/lancetgh on February 24, 2022 I declare no competing interests. Prevalence of hypoxaemia in children with pneumonia in low-income and middle-income countries: a systematic review and meta-analysisThe high prevalence of hypoxaemia among children with severe pneumonia, particularly among children who have been admitted to hospital, emphasises the importance of overall oxygen security within the health systems of low-income and middle-income countries, particularly in the context of the COVID-19 pandemic. Even among children with non-severe pneumonia that is managed in outpatient and community settings, the high prevalence emphasises the importance of rapid identification of hypoxaemia at the first point of contact and referral for appropriate oxygen therapy. Full-Text PDF Open AccessCorrection to Lancet Glob Health 2022; 10: e301–02Mvalo T. Need for routine pulse oximetry and oxygen delivery systems in low-income and middle-income countries. Lancet Glob Health 2022; 10: e301–02—In this Comment, the second sentence of the fourth paragraph should read "Studies in Africa have reported that patients with pneumonia who have SpO2 levels of 90–92% have similar risks of poor outcome to patients with SpO2 levels of less than 90%." This correction has been made as of Feb 24, 2022. Full-Text PDF Open Access